This NIH SBIR Phase I research will study the feasibility of using our recently developed large micropore volume activated carbon (LMPV-AC) material for medical oxygen gas storage applications. The proposed research is based on the fact that the proposed material possesses large micropore volume with relatively uniform pore size distribution and is able to adsorb/desorb a large amount of oxygen gas at a relatively small pressure. It is estimated that the proposed system could achieve the same oxygen storage density as that of a 150atm compressed cylinder with just 10-15atm pressure. With such low storage pressure, oxygen storage for home oxygen therapy will be safer, cheaper, and more convenient. It is also possible that the proposed system would be allowed in commercial airplanes, and the oxygen refill can be done at home safely with an oxygen concentrator. During Phase I research, the proposed carbon material will be optimized and characterized to achieve the best oxygen storage performance; the material's oxygen adsorption/desorption isotherms will be measured; the kinetic oxygen charge/discharge properties and related heat management will be studied; and the preliminary design of a LMPV-AC based low-pressure high-density oxygen storage system will be performed. The Phase I work will lay the background for the Phase II work, which will further develop and commercialize the proposed system. If successful, this research will lead to a low-pressure high-density oxygen gas storage system for the home oxygen therapy applications. With this system, potentially hazardus high pressure gas cylinders and troublesome liquid oxygen canisters can be eliminated. Therefore, the proposed technology will benefit to the home oxygen therapy patients, which is estimated to be 0.5 to 0.8 million people in the United States.